The present invention relates in general to a fast clamp occluder for medical fluid applications, and, more specifically, to a light weight clamp particularly useful for clamping a blood circuit in a blood perfusion system.
During cardiac bypass surgery, the heart is stopped in order to allow repair of defects, such as the replacement of defective heart valves, or the placement of bypass grafts. The patient's blood is redirected through an extracorporeal perfusion circuit typically including various items such as a venous cannula, flexible PVC tubing, a reservoir, a pump, an oxygenator, an arterial filter, and an arterial cannula. During extraction of blood from the patient and/or at various stages of flow within the perfusion circuit, air emboli may form within the circulating blood. If these emboli are not removed from the circulating blood and are instead introduced back to the patient's bloodstream, there may be serious complications.
An occluder (i.e., a clamp) is typically arranged around the tubing to function as a shutoff valve. It can be quickly actuated whenever emboli are detected in the blood so that blood flow is stopped before any emboli reach the patient. The occluder of present invention is also useful in connection with other procedures in which medical fluids flow through deformable tubing wherein the flow may be stopped by clamping down on the tubing.
Conventional clamps have included various electromagnetic and pneumatic devices designed to achieve very fast closing times. In order to generate and direct the forces necessary to achieve the fast closing times, conventional clamps have been relatively massive. Due to their weight, the clamping systems have typically required mounting support such as brackets suspended from a pole or fixture. The need for such a support limits the locations on the tubing of the blood circuit where the clamp can be conveniently installed, and it complicates the set-up of the perfusion circuit.
A typical electromagnetic clamp design passes the flexible tubing between a solenoid plunger and a wall surface. By activating the solenoid, the tubing is pinched against the wall to stop the fluid flow. If the tubing is not properly aligned with the plunger, however, the tubing may not become completely pinched off and there may be leakage.